ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
The widely accepted model descriptions of ion–molecule reactions suggest identical rate constants for the title reaction and the analogous, isoelectronic system N2++H2, which has been the topic of a previous publication from this laboratory. A comparison of both data sets, however, reveals substantial disagreement which we attribute to the absence of energetic resonances between the reagents which characterized the N2+/H2 system. Resonantly enhanced photoionization was exploited to accomplish the state-specific preparation of CO+ (X 2Σ+, v+=0,1). A monoenergetic beam of vibrationally selected ions, tuned within the range 0.01 eV≤Ecm≤10 eV, transits a scattering chamber which confines the neutral, H2. The title reaction was the only channel observed—no evidence of charge transfer or dissociative ionization could be detected. The hydrogen atom transfer turns out to proceed directly. The reactive cross section fails to show the E−1/2 dependence indicative of collision determined processes. The experimental data are perfectly mimicked by an expanded Langevin model which includes additional attractive potential terms. In contrast to the N2+/H2 case, vibrational excitation does not affect the rate of the reaction. © 1998 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.475416
